A Blob URL can violate origin attribute segregation, allowing it to be accessed from a private browsing tab and for data to be passed between the private browsing tab and a normal tab. This could allow for the leaking of private information specific to the private browsing context. This issue is mitigated by the requirement that the user enter the Blob URL manually in order for the access violation to occur. This vulnerability affects Firefox < 58.
Severity
CVSS 3.0
4.3 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS
1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)